Generally, almost 65% of the total calorie intake should be acquired from carbohydrates according to the standard nutritional guidelines. Proteins represent a very small portion in the ideal balanced diet while fat represents almost one-third of the total caloric content. MORE Â».
The trench is then backfilled, and additional material added to the top. Both of the Baltimore tunnels (the Harbor Tunnel and Fort McHenry Tunnel) used this method in their construction. The Harbor Tunnel, built in the mid-1950s, was considered an engineering marvel.
Designed by Ole Singstad, the tunnel was funded by the New Deal's Public Works Administration. Construction began on the first tube in March 1934. It opened to traffic on December 22, 1937, charging $0.50 per passenger car, equal to $8.2 today. The cost of construction was $85 million, equal to $1.5 billion today.